用HPLC测定苹果酒中的酚类物质

确立了用HPLC测定苹果酒中酚类物质的方法,各酚的回收率均在85％之上,说明该方法准确可靠。     

苹果酒中多酚及其褐变

多酚物质在酒的风味和颜色中起着十分重要的作用,由于其导致酒的褐变和混浊沉淀而被描述成“引起不稳定的因素”。主要对苹果酒中存在的多酚和影响多酚存在的因素进行讨论,同时对其在加工贮藏中引起褐变的机制和对褐变的抑制进行了论述。     

高效液相色谱法测定苹果酒中的多酚物质

建立了苹果酒中7种多酚物质的分析检测方法。使用该方法,各个多酚物质分离时间短,分离效果好,且回收率均超过80％、用该办法对自制苹果酒中多酚物质进行检测,得出样品中均有：儿茶素、咖啡酸、香豆酸等7种多酚物质。     

酵母菌种对苹果酒主发酵过程中的多酚组成及抗氧化活性的影响

通过研究国内外常用的4种酿酒酵母在苹果酒发酵过程中对多酚组成和抗氧化活性的影响,结果表明,在苹果酒发酵过程中,不同酵母对苹果发酵液中多酚总抗氧化能力的变化影响不大,但对鲜酒中多酚组成却有不同的影响。酵母菌1#（WLP775）、2#（#4766cider）发酵的苹果酒F1#、F2#在多酚组成上差异较大,抗氧化能力上差异亦较大;酵母3#（EXCE．SP）、4#（HARM-N°5）发酵的苹果酒F3#、F4#在多酚组成上差异较小,抗氧化能力上差异亦较小。     

红松种鳞中多酚HPLC指纹图谱的建立

建立红松种鳞中多酚HPLC指纹图谱分析方法。色谱条件为:C18反向色谱柱(200mm×4.6mm,5μm),以0.05%三氟乙酸溶液(A)和甲醇(B)作为流动相,洗脱梯度:0~11min,5%→15%B;11~16min,15%→17%B;16~23min,17%→23%B;23~36min,23%→35%B;36~50min,35%→40%B;50~65min,40%→50%B;65~70min,50%→5%B;流速为0.8mL/min,检测波长:280nm,该方法满足指纹图谱方法学考察。通过对8批样品的分析和比对,建立了红松多酚的指纹图谱,标示出14个稳定的共有峰,确定了咖啡酸为指纹图谱的参照峰。结果表明此方法简单、准确、重现性好,为红松多酚的质量控制标准提供了有效的方法。      

红松种鳞中多酚HPLC指纹图谱的建立

建立红松种鳞中多酚HPLC指纹图谱分析方法。色谱条件为:C18反向色谱柱(200mm×4.6mm,5μm),以0.05%三氟乙酸溶液(A)和甲醇(B)作为流动相,洗脱梯度:0~11min,5%→15%B;11~16min,15%→17%B;16~23min,17%→23%B;23~36min,23%→35%B;36~50min,35%→40%B;50~65min,40%→50%B;65~70min,50%→5%B;流速为0.8mL/min,检测波长:280nm,该方法满足指纹图谱方法学考察。通过对8批样品的分析和比对,建立了红松多酚的指纹图谱,标示出14个稳定的共有峰,确定了咖啡酸为指纹图谱的参照峰。结果表明此方法简单、准确、重现性好,为红松多酚的质量控制标准提供了有效的方法。     

HPLC法分离鉴定樟子松树皮多酚研究

使用高效液相色谱法对樟子松树皮中多酚类化合物进行分离及鉴定,考察了高效液相最佳的检测波长,优化了洗脱剂、酸、流速、柱温、进样量对多酚分离效果的影响。结果表明,在波长为280nm条件下,流动相为甲醇-水（0.05%TFA）,流速为1.0mL/min,柱温为30℃,进样量为5μL时,色谱峰的分离效果好,峰形最佳。通过与标准样品进行比对鉴定后发现,樟子松树皮中含有七个单体酚,分别为对香豆酸、儿茶素、咖啡酸、芦丁、绿原酸、没食子酸、肉桂酸,其中对香豆酸和儿茶素的含量较高。      

普洱茶贮藏过程中含水量与多酚变化的相关性分析研究

普洱茶是云南省极具代表性的产品,具有较高的养身、贮藏价值,在我国茶叶市场份额中占比较高,用其制成的茶汤色泽明亮、滋味醇厚,更有清胃生津、去油解腻的功效。当前伴随产业规模扩大、竞争格局调整,生产经营者对于普洱茶蕴藏的经济、文化价值有了更为全面、深刻的认知,相关工艺体系也不断成熟。本文主要聚焦普洱茶贮藏过程,对其含水量、多酚变化状况、相关性特征等进行研究,结果表明,水分是促成普洱茶多酚类物质转化的重要因素,水分的增加有助于加快普洱茶发酵进程,缓解其苦涩口感,同时促进茶色素的累积。因此,在加工、渥堆过程中,要科学控制含水量,促进其滋味品质的提升。     

优良苹果酒酵母的筛选研究

采用本实验室保藏的10株酵母（P6、P8、P11、P15、P25、W38、W41、W41、W52和W65）为备选菌株,以专用啤酒酵母7^#和 葡萄酒酿酒酵母3^#为对照,通过系统试验,包括试验酵母菌落形态和感官评价、发酵能力比较和发酵所得苹果酒品质的评价,筛选出一株最佳苹果酒酿酒酵母W41,其发酵的原酒酒精度达133.0 mL/L,酒体澄清透明,具有苹果酒的典型风味.     

苹果酒发酵过程中酵母营养的研究

苹果汁发酵常出现发酵迟滞或停滞的现象,影响苹果汁发酵迟滞或停滞的主要原因是酵母的营养问题,即可同化氮源和维生素。为此,本文通过单因素试验研究了磷酸氢二铵（DAP）、硫酸铵、硫胺素、肌醇、烟酰胺、吡哆醇、生物素、泛酸等八种营养素对发酵的影响。结果表明,磷酸氢二铵（DAP）、硫酸铵、硫胺素及生物素的添加都对酵母代谢有显著影响,当添加量分别为400、1200、0．30及0．20mg／L时,酒精度达到最大值,酵母代谢最为旺盛。     

苹果酒高级醇生成控制的研究

通过单因素试验和响应面分析,研究了接种量、（NH4）2HPO4添加量、发酵温度、果汁糖度及初始pH值等因素对高级醇生成的影响。研究发现,接种量、（NH4）2HPO4添加量、初始pH值是高级醇生成的主要影响因素;高级醇生成量最低的发酵条件为：接种量9.3%、（NH4）2HPO4添加量155mg/L、初始pH值3.3、初始糖度16g/100mL、发酵温度18℃。     

苹果酒中高级醇生成的研究

通过单因子试验及正交试验,研究苹果酒酿造过程中苹果汁初始pH值、发酵温度、酵母接种量、加(NH4)2H PO4量等不同因素对高级醇生成的影响。研究发现,外加氮源、较低的pH及发酵温度对高级醇的生成都有很好的抑制作用,确定在实验条件下,高级醇生成量最低的酿造工艺:发酵温度20℃、酵母接种量为0.10%、加(NH4)2H PO4量为200m g/kg、苹果汁初始pH值为3.3。     

生物量移除技术发酵低醇苹果酒

本研究采用生物量移除技术发酵低醇苹果酒,为低醇苹果酒的研究和开发提供技术参考。实验利用离心将发酵液中的酵母移除一部分,使滤液中还保持有一定量酵母,维持后发酵。实验分析了酵母移除的最佳时间和移除量,得出1.5d～2.0d后移除酵母最合适,离心后活酵母数在106cfu/mL数量级合适。通过该方法,得到了果味丰郁,低酒精度的甜型苹果酒。     

苹果酒生产技术研究

以苹果为原料,采用液态法发酵生产苹果酒,结果表明:苹果在破碎时加入0.2%异Vc护色,并加入0.03%果胶酶,过滤得到苹果汁,0.02%自选酵母菌种A-9958在20￣25℃发酵,加入适量砂糖,可酿造出苹果酒。     

Screening of cider yeasts for sparkling cider production (Champenoise method)

A total of 350 colonies isolated from a cider cellar in Asturias (Spain) were identified by rDNA ITS-RFLP restriction analysis. Saccharomyces spp. strains were characterized by mitochondrial DNA (mtDNA) restriction analysis. Fifty-four different Saccharomyces spp. strains were identified and tested to ascertain their capacity to carry out secondary fermentation of sparkling ciders. The screening of yeasts to determine their principal enological characteristics (tolerance to ethanol, production of volatile acidity and hydrogen sulphide) was accomplished by means of rapid, non-expensive assays (plate agar). As a result, 13 (24%) of the 54 initial Saccharomyces spp. yeast strains were eliminated. The technological properties assessed were flocculation capacity, ethanol and sulphite tolerance, and production of major volatiles. Ten Saccharomyces cerevisiae strains were characterized as true flocculants; all of these strains were able to grow in ethanolic medium and in the presence of 200mg/l of sulphite. Applying cluster analysis to the production of amyl alcohols, isobutanol, propanol and 2-phenylethanol, the strains were classified in two natural groups. Two flocculent yeast strains referred to as 3' and 50', representative of the each statistical group, were selected together with two reference strains (Saccharomyces bayanus C6 and S. cerevisiae Levuline CHP) to elaborate four sparkling ciders by the Champenoise method. The analysis of variance (p<0.01) among ciders revealed that glycerol, acetaldehyde, ethyl acetate, methanol, propanol, i-butanol and 2-phenylethanol were significantly influenced by the secondary yeast strain. The results of sensory analysis indicated that all the sparkling ciders were scored as good. No significant differences among sparkling ciders were found for odour attributes and taste intensity.     

苹果醋肽饮料的研制

介绍了以苹果醋为主要载体并配以一定数量的大豆多肽．然后与苹果汁、蜂蜜、低聚异麦芽糖、维生素B族、维生素C、果溶Ca等辅助成分进行科学调配生产苹果醋肽饮料的工艺流程．     

Phenolic compounds in coffee pulp: Quantitative determination by HPLC

The content of phenolic compounds tentatively identified by HPLC in fresh coffee pulp gives an average composition in the 12 cultivars studied as follows: chlorogenic acid (5-caffeoylquinic acid), 42·2%; epicatechin, 21·6%; isochlorogenic acid I, 5·7%; isochlorogenic acid II, 19·3%; isochlorogenic acid III, 4·4%; catechin, 2·2%; rutin, 2·1%; protocatechuic acid, 1·6%; and ferulic acid, 1·0%. When the percentages of chlorogenic and isochlorogenic acids are added to the corresponding one of epicatechin for each cultivar, it is found that they make up between 92·0% and 98·4% of the total of identified phenolic compounds. Qualitative or quantitative differences were not detected between cultivars of coffee plants resistant and susceptible to coffee leaf rust.     

野生苹果酒产香酵母的分离及筛选

从苹果园土壤中经多次稀释涂布分离出多株酵母菌,根据菌落形态、显微观察以及平皿的香味评定初筛出4株产香酵母,通过性能测定,测出这4株菌能耐受160 mg/LSO2和10%vol酒精度。然后经混合发酵试验所得苹果酒综合评价,筛选出J-4号菌较其他菌株更适合作为苹果酒酿造的产香酵母,其发酵所得苹果酒品质优,具有苹果酒的典型风味,适用于苹果酒生产。对J-4进行分子鉴定,鉴定结果表明其为孢汉逊酵母属,与Hanseniaspora thailandica AB501147.1为同一种。     

Determination of organic acids evolution during apple cider fermentation using an improved HPLC analysis method

An efficient method for analyzing ten organic acids in food, namely citric, pyruvic, malic, lactic, succinic, formic, acetic, adipic, propionic and butyric acids, using HPLC was developed. Boric acid was added into the mobile phase to separate lactic and succinic acids, and a post-column buffer solution [5 mmol/L p-toluensulfonic acid (p-TSA) + 20 mmol/L bis (2-hydroxyethyl) iminotris (hydroxymethyl) methane (bis–tris) + 100 μmol/L sodium ethylenediaminetetraacetic (EDTA-2Na)] was used to improve the sensitivity of detection. The average spiked recoveries for the ten organic acids ranged from 82.9 to 127.9% with relative standard deviations of 1.44–4.71%. The linear ranges of determination were from 15 to 1,000 mg/L with correlation coefficients of 0.9995–0.9999. The metabolism of organic acids in cider, and the effect of nutrients including diammonium phosphate (DAP), thiamine, biotin, niacinamide and pantothenic acid on their metabolism, were studied using this method of analysis. We found that before cider brewing, additions of 200 mg/L DAP and 0.3 mg/L thiamine to apple juice concentrate results in a high quality cider. F. Zhou and B. Ji contributed equally to this work.